rsync-3.0.9-precise-detect-renamed.diff.txt - This patch...

This patch adds the --detect-renamed option which makes rsync notice files
that either (1) match in size & modify-time (plus the basename, if possible)
or (2) match in size & checksum (when --checksum was also specified) and use
each match as an alternate basis file to speed up the transfer.
The algorithm attempts to scan the receiving-side's files in an efficient
manner. If --delete[-before] is enabled, we'll take advantage of the
pre-transfer delete pass to prepare any alternate-basis-file matches we
might find. If --delete-before is not enabled, rsync does the rename scan
during the regular file-sending scan (scanning each directory right before
the generator starts updating files from that dir). In this latter mode,
rsync might delay the updating of a file (if no alternate-basis match was
yet found) until the full scan of the receiving side is complete, at which
point any delayed files are processed.
I chose to hard-link the alternate-basis files into a ".~tmp~" subdir that
takes advantage of rsync's pre-existing partial-dir logic. This uses less
memory than trying to keep track of the matches internally, and also allows
any deletions or file-updates to occur normally without interfering with
these alternate-basis discoveries.
To use this patch, run these commands for a successful build:
patch -p1 <patches/detect-renamed.diff
./configure (optional if already run)
make
TODO:
We need to never return a match from fattr_find() that has a basis
file. This will ensure that we don't try to give a renamed file to
a file that can't use it, while missing out on giving it to a file
that could use it.
based-on: 40afd365cc8ca968fd16e161d24df5b8a8a520cc
--- a/compat.c
+++ b/compat.c
@@ -41,6 +41,7 @@ extern int read_batch;
extern int delay_updates;
extern int checksum_seed;
extern int basis_dir_cnt;
+extern int detect_renamed;
extern int prune_empty_dirs;
extern int protocol_version;
extern int protect_args;
@@ -124,6 +125,7 @@ void set_allow_inc_recurse(void)
allow_inc_recurse = 0;
else if (!am_sender
&& (delete_before || delete_after
+ || detect_renamed
|| delay_updates || prune_empty_dirs))
allow_inc_recurse = 0;
else if (am_server && !local_server
--- a/flist.c
+++ b/flist.c
@@ -61,6 +61,7 @@ extern int non_perishable_cnt;
extern int prune_empty_dirs;
extern int copy_links;
extern int copy_unsafe_links;

+extern int detect_renamed;
extern int protocol_version;
extern int sanitize_paths;
extern int munge_symlinks;
@@ -121,6 +122,8 @@ static int64 tmp_dev = -1, tmp_ino;
#endif
static char tmp_sum[MAX_DIGEST_LEN];
+struct file_list the_fattr_list;
+
static char empty_sum[MAX_DIGEST_LEN];
static int flist_count_offset; /* for --delete --progress */
static int dir_count = 0;
@@ -288,6 +291,45 @@ static int is_excluded(const char *fname
return 0;
}
+static int fattr_compare(struct file_struct **file1, struct file_struct **file2)
+{
+ struct file_struct *f1 = *file1;
+ struct file_struct *f2 = *file2;
+ int64 len1 = F_LENGTH(f1), len2 = F_LENGTH(f2);
+ int diff;
+
+ if (!f1->basename || !S_ISREG(f1->mode) || !len1) {
+ if (!f2->basename || !S_ISREG(f2->mode) || !len2)
+ return 0;
+ return 1;
+ }
+ if (!f2->basename || !S_ISREG(f2->mode) || !len2)
+ return -1;
+
+ /* Don't use diff for values that are longer than an int. */
+ if (len1 != len2)
+ return len1 < len2 ? -1 : 1;
+
+ if (always_checksum) {
+